gibson



Feb. 23, 1932. v G. H. GIBSON Re. 18,356

COMBUSTION CONTROL FOR GAS PRODUCERS Original Filed May 28, 1917 3Sheets-Sheet l 3nventor GEORGE 6/4301! (Ittorneg Feb. 23, 1932. G. H.GIBSON 18,356

COMBUSTION CONTROL FOR GAS PRODUCERS Original Filed May 1917 3Sheets-Sheet 2 a/MM (lttorneg Feb. 23, 1932. G G|B$ON Re. 18,356

COMBUSTION CONTROL FOR GAS PRODUCERS Original Filed May 28, 1917 3Sheets-Sheet 3 3nnent or GEMEHG/M/x v V J attorney maintaining ReisauedFeb. 23, 1932 GEORGE H. GIBSON, OF UPPER MONTCLAIR, NEW JERSEYCOMBUSTION CONTROL FOR GAS PRODUCERS Original No. 1,523,414, datedJanuary 20, 1925, Serial No. 171,401, filed May 28, 1917. Renewed June2, 1924. Application for reissue filed October 16, 1931, Serial No.569,323.

A primary object of my present invention is to provide improved meansfor regulating the operation of a gas producer in Which a diluent, suchas steam or products of combustion, as well as primaryairare supplied tothe producer. Another primary object of the invention is to provideimproved means for regulating combustion apparatus comprising a gasproducer and a separate combustion furnace in which the gas generated inthe producer is added to, and burned with the proper amount ofsecondaryair which may or may not be mixed with a diluent; and a thirdprimary object of the invention is to provide improved means forautomatically redetermined ratios between fluid rates of ow which arewell adapted for use in automatically proportioning the primary air anddiluent in attaining the first mentioned object of my invention, and foruse in proportioning the gas generated by the producer and the secondaryair for its comustion in attaining the second mentioned primary objectof my invention.

The various features of novelty which characterize my invention arepointed out with particularity in the claims annexed to and forming partof this specification. For a better understanding of the invention, itsoperating advantages, and specific objects obtained by its use,reference should be had to the accompanying drawings and descriptivematter, in which I have illustrated and described preferred embodimentsof my in vention.

Of'the drawings: Figure 1 is a diagrammatic representation of a gasproducer provided with one form of my improved regulating means.

Figure 2 is a simplified diagram of certain electrical connections andarrangements emfurnace heated with the gas generatedthereby.

Figure 5 is a sectional elevation of a diflerential pressure deviceemployed in the plant i shown in Figure 4.

Figure 6 is a diagrammatic representation PATENT OFFICE of a power plantcomprising a gas producer and a steam generating boiler heated by thegas generated in the producer.

In the drawings, and referring first to the apparatus shown in Figs. 1,2 and 3, A represents a gas producer of conventional type, having theusual charging provisions at its upper end, and open at its lower end topermit air to pass into the charge through the grate A. The finish gasis withdrawn from an intermediate zone of the producer to an annularchamber Asurrounding the roducer and connected to the service main Therich gas given ofl by the freshly charged fuel at the top of theproducer leaves the latter through the outlet A and passes through theconduit C to the linet A through which it is returned to the lower endof the producer above the grate A. Steam suppliedby the pipe D, whichterminates in a restricted discharge nozzle D, is also blown into thelower end ofthe producer through inlet A The jet of steam thus suppliedprovides the necessary draft for withdrawing the rich gas from the topof the producer through the outlet A and conduit 0, and also insures atemperature in the fuel bed below the fus- 7 ing point of the ash. Bycausing the rich gas given off at the top of the producer to be passedthrough the fuel bed again in this manner the tars and vapors containedin the rich gas are broken up and converted into. permanent gases, andin consequence the gas withdrawn from the producer through the servicemain B is composed almost entirely of fixed permanent gases suitable foruse in a gas engine or for similar purposes.

Associated with the producer shown in Fig. 1 are means for automaticallyproportioning the amount 'of rich gas withdrawn from the top of theproducer, the amount of primary air supplied to the bottom of thevproducer, and the amount of steam supplied by the steam jet D, each tothe amount of gas ,7

withdrawn through the servicemain B, so as f to maintain predeterminedratios between each pair of these four different fluid streams;

as the amount of gas withdrawn from the producer through the, main Bvaries. The means which I employ for this purpose comprise a flowmeasuring device for measuring the amount of gas withdrawn through themain B; a flow measuring device for measuring the flow of rich gasesthrough the conduit C; a flow measuring device for measuring the steamflow through the conduit D; a device for regulating the flow through theconduit C; a device for regulating the flow of steam through the conduitD, and means by which the various flow measuring devices actuate the twoflow regulating devices to maintain the flows controlled respectively bythe latter each in a predetermined ratio tothe flow of gas through themain B. The regulating means specified so regulate thedraft through theproducer as to make the amount of primary air drawn into the lower endof the producer throu h the grate A propcfi'tional to the gas out owthrough the ipe p The flow measuring device employed for measuring theflow through the conduit B comprises a Venturi tube section B in theconduit B, and a differential pressure responsive device E, having twochambers e and e separated by a diaphragm E To the center of thediaphragm E? is secured an operating stem E. This stem extends inopposite directions from the diaphragm and passes at'its outer end by ahead through which the corresponding portion of the stem E passes and towhich the latter is rigidly secured, thus making stufiing boxesunnecessary.

The chamber e is connected to a high pressure point of the Venturi tubesection B by a pipe E, and the chamber 6. is connected to the lowpressure point of the section by a pipe E. The upper end of thestem E isconnected to a regulating switch member F. As shown, the regulatingmember F is in the form of a bell crank'lever, pivoted at F. One arm ofthe member F is'a switch arm which is arranged to sweep over anelectrical resistance G, and is rovided with an adj ustablecounter-weight F for varying the force which must beexerted on thediaphra m E to produce a particular movement of t e de-. pending arm ofthe member F over the resistance G.

The device for measuring the flow through the conduit C comprises aVenturi tube section C in the latter, and a differential pressure deviceE having its two chambers con- 'nected by the pipes E and E to the highand low pressure points of the Venturi tube section. This difl'erentialpressure device is employed to adjust a regulating switch element FAsweeping overa resistance GA generally similar to the regulating memberF and resistance G, respectively.

The means for measuring the steam flow through the conduit D comprises adifl'erential pressure device E, having its chamber e connected by aconduit E to the conduit D and having its chamber e connected by aconduit E to the outer end of the producer inlet A The difierential ofthe pressure transmitted through the pipes E and-E to the two chambersof the corresponding differential device E is a function of the steamdischarge through the nozzle D. This differential pressure deviceadjusts a switch arm FB, working along a resistance GB, and generallysimilar respectively to element F and resistance'G.

The flow through" the conduit C is regulated by a damper G which isadjusted by means of an intermittently actuated reversible electricmotor H. The latter is energized by a source of current H, having oneterminal connected to one terminal of the motor and the other terminalconnected to a circuit closin device I, which, as illustrated, is formedby, or carried on the armature I of a polarized relay IA. When thelatter is energized by a current flow through its winding in onedirection the armature I is raised and thereby connects the currentsource H to a terminal contact H of the motor H. On-a reverse currentflow through the winding of the relay IA, the armature I is depressedand the current source H is connected by the armature I to another motorcontact H When the current source H is operatively connected to themotor through the contact H; the motor H operates in the directionrequired to close the damper C and thereby reduces the flow through theconduit C. When the current source H is operatively connected to themotor through the contact H, the motor H operates in a direction to openthe damperC and thereby permits an increased flow through the conduit C.

The flow through the conduit D is controlled by a damper D adjusted by amotor H controlled by a polarized relay IB through means similar tothose by which the relay IA controls the motor H for regulating thedamper C Circuit connection 1 connects the resist ance elements G, GAand GB in multiple to a source of current J, as shown most clearly inFig. 2. Advantageously the multiple circuits connecting'the resistancesG, GA and GB with the current source J include manually adjustableresistance K, KA and KB respectively. The switch arm F is connected byconductor 2 and branch conductors 2 and 2 respectively -to the switcharms FA and FE. The branch conductor 2- includes the winding of thepolarized relay IA, and

the branch conductor 2 includes the windin of the polarized relay IB.

llVith the construction described the position of the switch arm Fdepends upon the difference in pressure between the high and lowpressure points of the Venturi section, and this pressure difierentialissome function of fluid rate of flow through the conduit B. No matterwhat the flow law governing .the flow through the conduit B may be, itis possible to make such a disposition of the various portions of theresistance conductor G along the path of the switch arm F that the whoofthe portion of the resistance G at one side of the switch arm F to theportion at the other side of the arm may be made to vary with anydesired function of the varying rate of flow through the conduit B, andin particular it can be made to vary in linear proportionto the rate offlow through the conduit. The electric potential difference between theswitch arm F and either terminal of the current source J may thus bemade proportional to the current flow through the conduit B. Similarlythe potentials of the switch arms FA and FE may be made linearlyproportional, respectively, to the rates of flow through the conduits Cand D regardless of whether the flow laws governing the flow throughthese conduits are the same as or different from those gov erning theflow through the conduit B.

When the three switch arms F, FA and FE are all at the same potential nocurrent will flow through either of the polarized relays IA and IE, butif the switch arm FA differs in potential from either of the switch armsF and FE a current will flow through the branch conductor 2*. This willenergize the relay IA in one direction or the other, according to thedirection of the current flow, and the parts are so arranged that theconsequent energization of the motor H regulating the damper C willadjust the latter to increase or decrease the How through conduit C asmay berequired to thereby move the switch arm FA in the directionnecessary to make the potential of theswitch arm FA the same as that ofthe switch arms F and FE. Similarly a difference between the potentialof the switch arm FE and the potential of either switch'arm F or FA willresult in a current flow through the conductor 2 energizing thepolarized relay TB in the direction required to effect an adjustment ofthe damper D tending to make the flow in the conduit D such that thepotential of the switch arm FB will be the same as the potential of theswitch arms F and FA.

Those skilled in the art will understand that by adjusting the settingof the counter weights F? and the manually adjustable resistances K, KAand KB, coupled with a suitable disposition of the various resistanceconductors G, GA and GB, the ratio of the tiometer resistances.

flow of the steam, rich gas or primary air to the flow of gas through.the conduit B may, for any given rate of flow through the latter, bemade of any desired value, within limits, and these ratios ma be keptconstant or varied as the rate of ow through the conduit B varies.

The means employed in the apparatus shown in Figs. 1, 2 and 3 tomaintain predetermined ratios between different fluid rates of flow maybe calledpotentiometer means, inasmuch as the flow regulating meansproper are responsive to differences in potentials between particularpoints (determined by the flow measuring devices) of the resistances G,GA and GB, which may be called the poten- This potentiometer means iscomparatively simple and may readily be made highly sensitive, accurateand reliable since the various potentiometer resistances are connectedin multiple to a single source of current. The operation of theproportioning means is independent of the actual voltage of the sourceof current,

and is not affected by variations in that volt- 1 age.

. Furthermore the'operation of the flow proportioning apparatusisindependent, within practical limits, of the resistance in the circuitsincluding relays IA and IB, and hence does not depend upon the characterof the contacts which the various switches F, FA,

and FE make with the corresponding potentiometer resistances G, GA andGB respectively. All that is necessary is that the contacts be goodenough to pass some current when a difference in potential exists. Therelays IA and IB may be so wound that only a very minute current flow isrequired to make them effective to set in action the more powerfulelectric motors H or other motors which may be employed to actuate thedifferent flow regulating devices. The ease with which the potentiometerresistances may be disposed to obtain a predetermined potentialvariation in response to the particular rates of flow through thecorresponding con.-

duits makes the potentiometer means of proportioning readily applicableto use with fluids and flow measuring devices differing widely incharacter.

The mode of operating a gas producer made possible by the use of theapparatus.

in the producer AA is withdrawn from the latter through the conduit BBconnected to gas inlet of the furnace L the gas supplied.

the upper end of the producer AA, and is dehvered to the gas inlet of anindustrial furnace such as a reheating furnace L. At the by the conduitBB is mixed with air supplied by the blower P, and drawn into the latterthrough the conduit 0A. The air thus drawn into the blower P is mixed inthe latter with a portion of the products of combustion issuing from thefurnace L through the conduit M the latter being connected to the inletof the blower P by a conduit O. The portion of the products ofcombustion issuing through the conduit M and not returned to furnace L,through the conduit 0, passes into the loopedconduit M disposed withinand forming a part of an air plreheating device N. The latter has aninlet I which may be open to the atmosphere and an outlet N to which theconduit OA is connected. The primary air supplied to the furnace throughthe conduit 0A and blower P is thus preheated by the products ofcombustion in its passage through the preheater N. The looped conduit Mdischarges into n the chimney connection M. A portion of the gaseousproducts of combustion thus passing to the chimney connection M, iswithdrawn from the latter through the conduit M, which "is connected tothe inlet of a blower PA,

which also draws in cold atmospheric air through the conduit Q, anddelivers the mixture of cold air and cooled products of combustion tothe primary air supply pipe A" of the producer AA.

The apparatus shown in Fig. 4 comprises means for maintaining apredetermined relation between each of the fluid rates of flow throughthe conduits 0, 0A, M and Q and the temperature of the products ofcombustion adjacent the outlet for the latter from the furnace L. Themeans employed for this purpose comprise pyrometric means including, asshown, a thermo-couple located at the appropriate point in the furnaceL, and comprises a flow measuring and flow regulating device for each ofthe conduits in which the flow is re" lated, and comprise electricalmeans by w ich each flow regulating device is jointly controlled by thepyrom- VICE.

eter V and the corresponding measuring deinthe upper wallof the casing.Located in the casilig and telescoping with the tubular element 21 is ahollow annular floating member E open at its lower end. A stem or ocrating rod E passes into the casing E through the open ended tubularelement E, and is connected to the annular member E" lower end of, butdoes not close the central passage through the annular member E. Aconduit E leads from the upper portion of the member E to the highpressure point of the corresponding Venturi tube section, and a conduitE leading from the low pressure point of the corresponding Venturi tubesection passes into the chamber E -through the bottom wall of the latterand projects up into the upper portion of the annular space within themember E Water, or other sealing liquid, partially fills the casing Eand closes communication between the space in the latter above theliquid level, and the exterior of the member E", and the passageway outof the casing through the tubular member E Those skilled in the art willunderstand that this form of differential pressure device is a verysensitive and reliable one.

Associated with each of the conduits 0, 0A, M and Q is a' otentiometerresistance GC, GD, GE and F respectively. 000 crating with theresistance conductors G8, GD, GE and GF are regulatingswitch members FC,FD, FE and FF respectively, each of which may be similar in constructionto the switch member F, first described, and is connected tothe 0 ratingstem E" of the corresponding di erential pressure device EA as theswitch member F is connected to the stem E of the differential pressuredevice E in Fig. 1. 3

- The various resistance conductors GC, GD, GE and GF are connected inmultiple with a source of current J A by conductors ,3. Sepathereof anadjustable connection K is made to one side of each of the resistancesGC, GD,

GE and GF. A potentiometer resistance conductor GH, one of the terminalsK of which is adjustable, is also connected to the source of current JAin multiple with the other potentiometer resistances. Coo rating withthe resistance GH is a switc FH of the teeth of the ratchet wheel R andgives the latter a slight angular movement in the clockwise direction.Similarly the armature S of the coil SB carries a pawl S which engages astop S and is thereby held out of engagement with the ratchet wheel Bwhen the coil SB is deenergized, but when the latter is energized,engages one of the teeth of the ratchet wheel and gives the latter asmall angular movement in the counter clockwise direction.

Theenergization of the coils SA and SB is intermittently effected whennecessary by the following means: The movable coil U of the electricalinstrument U, to which the terminals of the thermo-couple V areconnected supports an arm U carrying at its free end a transverseflexible contact device'U which normally lies between a pair of lugs Tand T carried by a lever T. The latter is oscillated by a continuouslyoperating electric motor HH, and a gear wheel H rotated by the motor andconnected to the lever T by a crank pin H and connecting rod T As thelever T approaches the instrument U in each of its oscillatorymovements, one or the other of the lugs T and T engage the correspondwing end of the flexible contact member U and 'U and to the secondcontact U forces the latter into engagement with the corresponding pairof contacts U and U in case the pointer arm U is deflected up or downrespectively from the neutral position illustrated in Fig. 4. When thearm U is in aneutral position the lugs T and 'I clear both ends of thecontact piece U One of the contacts U is connected to one terminal ofthe coil SB, and one of the contacts U is connected to one terminal ofthe coil SA. The other terminals of the coils SA and SB are connected toone side of a source of current J B,andthe other side of the source ofcurrent JB is connected to the second contact The source of current JBalso energizes the motor HH.

The-switch arm FHisconnected by a con ductor 4 and branch conductors 4C,4D, 4E and 4F to the switch members FC, FD, FE

I v and FF respectively. The conductor 40 includes the winding of apolarized relay IC, which controls a motor HG for adjusting a damper Oin the conduit 0 exactly as the damper C is controlled by the relay IAin the apparatus shown in Fig. 1, and the conductors 4]), 4E and4F'include the windings of relays ID, IE and IF, respectively whichsimilarly control dampers O, M and Q in the conduits OA, M and Qrespectively.

Theapparatus shown in Fig. 4 is intended to maintain a constanttemperature at the the thermo-couple V is located. So long as thistemperature does not vary from the predetermined normal amount, thepointer arm U of the instrument U will remain in its neutral position inwhich the oscillations oftlfe lever T will not result in energizingeither of the solenoid coils SA and SB. lVhen the temperature risesabove the normal, pointer U will be shifted in the clockwise direction,and when thereafter the lever T next approaches the instrument U, thecoil SB will be momentarily energized and the ratchet wheel R therebydisplaced from its normal position by a small angularmovement in thecounter clockwise direction. This will shift thelever FH andcorrespondingly vary the potential of the latter. The variation inpotential of the lever FH thus produced will result ina current flowthrough the relays IC, ID, IE and IF in a direction tending to cause 'aclosing movement of the various dampers O, O M and Q and thereby reducethe amount of gas generated, in the producer AA, and the amount of heatgenerated in the furnace L by the combustion therein of the gas so pro:duced. In case this initial adjustment is not sufiicient to reduce thetemperature in the furnace L to normal, a succeedin oscillator movementof the lever T towar the instrument U will again energize the coil SBandcause a further angular adjustment of the ratchet wheel R in a counterclockwise direction and a consequent further throttling ad justment ofthe various dampers O O, M and Q These throttling adjustments will becontinued until the temperature of the thermo-couple V is returned tothe predetermined normal value, whereupon the pointer arm U and thecontact U carried thereby return to their neutral positions. Should thetemperature of the thermo-couple V fall below normal the correspondingdisplacement of the pointer'arm U and contact piece U will result in theenergization of the solenoid coil SA one or more times andacorresponding angular adjustment or adjustments of the ratchet wheel Rin a clockwise direction. The change in potential of the switch arm FHthus produced will result in currentflows through the relays IC, ID, IE,and IF necessary to produce openin adjustments of the dampers O 0, M andcrease the amount of gas generated in the producer AA and burned in thefurnace L until the temperature of the thermo-couple V again becomesnormal. 7

It will be understood without further explanation that the flowmeasuring and controlling means associated with the'conduits M and Qwill maintain at all times the, de-

Q, and thereby in--' sired relative proportions between the pri-' maryair supplied through the conduit Q, and

end of the producer AB. This end of the gas producer AA; The flowmeasuring and controlling devices associated with the conduits O and 0Asimilarly maintain the desired ratio between the amounts of preheatedair supplied by the conduit OA and the heated diluent supplied by theconduit 0 to the blower P and passed by the latter to the furnace L.Since the gas generated in the producer is proportioned to the air anddiluent supplied to the producer, the instrumentalities described willmaintain the desired ratio between the 'gas passed to the furnace L fromthe producer through the conduit BB, and the mixture of air and diluentpassed to the furnace through the blower P. The -addi-.

tion of the diluent to the air supplied to the furnace L through theblower P elongates the combustion flame in the furnace and tends toproduce an equality ,of temperature in the .furnace. The normaltemperature main tained in the furnace L may be adjusted when desired byadjusting the pointer arm U with I relation tothe movable coil U of theinstrument U.

In Figure 6 I have illustrated the use of my invention to control theoperation of a steam plant compris'ing'a steam generating furnace W,heated by the combustion of gas generated in a producer AB from whichthe gas generated passes through a conduit BC to the combustion chamberW of the steam generating furnace, where it is admixedby air supplied bya conduit P, the draft being created by a blower PC. The ainLthuspassing' to the combustion chamber is preheated by passing through onesection P of the preheater located in the products of combustion outletW from the furnace W. Only a portion of the air passing through thepreheater section P is delivered to the conduit P The remainder of theair preheated in the section P Ipasses through a second preheatingsection 2 and is further preheated therein. and is delivered to aconduit P, which supplies primary air to the lower mitted to theproducer through tuyer s A" opening from a bustle chamber A sufjxundingthe producer and into which the nduit 'P discharges. By the use ofprimary air thus preheated the ash formed'in the producer may be causedto fuse and flow out of the bottom of the producer proper into the ashpitA", from which it may be removed from time to time through thenormally closed outlet A.

The conduit P includes a Venturi section P, associated with which is adifferential pressure device EA connected with a regulating switch FI,working over a potentiometer resistance GI. The flow through the con-'larized relay II. Similarly the conduit P is adincludes a Venturisection P associated with which is a differential pressure device EA,controlling a regulating switch FJ working over a potentiometerresistance GJ. The flow throu h the conduit P is regulated by a damper 8adjusted b a motor H, controlled by a polarized re ay IJ. The steamoutlet pipe W from the steam generating furnace WV includes a Venturitube section W, associated with which is a diiferential pressure deviceE which adjusts a regulating switch FK working over a potentiometerresistance GK. The various resistances GI, GJ and GKare connected inmultiple to a source of current J C by conductors 5, and in this form ofmy invention the source of current J C- also supplies the current forenergizing the damper actuating motors H. The switch member FK isconnected by the conductor 6 and the branch conductors 6 and 6. to theregulating switch members FI and FJ, respectively. The conductor 6includes the winding ofthe polarized relay II, and

It will be apparent without further expla-' nation that the apparatusshown in Fig. 6 comprises means for proportioning the amount of airsupplied to the producer AB and the amount of air supplied to thecombustion chamber W each to the amount of steam withdrawn from theboiler through the steam pipe W The producer gas fired, steam generatingplant shown in Fig. 6, with its highly efficient automatic controlprovisions possesses special operating advantages in that it is possibleto locate the steam generating furnace adjacent the turbines or othersteam utilizing devices supplied, and to locate the producer at somemore remote steam generating furnace is enhanced by the fact that thecharacter of the combustion minimizes the accumulation of dust or otherforeign material on the boiler tubes.

Those skilled in the art will recognize that the flow proportioningmeans employed with all the forms of apparatus disclosed herein areessentially simple and reliable. The different fiow proportioninginstrumentalities are comparatively simple, compact and reliable and areof the character to permit their ready installation in connection withexist ing flow systems as well as in new plants.

While in accordance with the provisions of the statutes I haveillustrated and described the best forms of my invention now known tome, those skilled in the art will understand that changes may be made inthe form of the apparatus disclosed herein without departing from thespirit of the invention covered by myclaims and that certain features ofmy invention may sometimes be used to advantage without a correspondinguse of other features.

lml

and convenient place. The efliciency of the Having now described myinvention what I claim as new and desire to secure by Letters Patent,is:

' 1. In combination a gas producer having an air inlet, a gas outlet anda fuel bed interposed between said inlet and outlet, a separatecombustion furnace, to which said gas issuing from said producer throughsaid outlet is passed, an air inlet to said furnace and means includinga separate regulating mechanism for each, air inlet for automaticallyproportioning the air supplied to theair inlet of the producer to theair supplied to the air inlet of said furnace, each of said mechanismscomprising means for establishing a measure of the rate of air supply tothe corresponding air inlet and a measure of a normal value of said rateand means operating on any variation in the ratio of said-measures fromapredetermined value for correctively adjusting the last mentioned rateof air supply until said ratio value is restored.

2. In combination a gas producer having an air inlet, a gas outlet and afuel bed interposed between saidinlet and outlet, a separate combustionfurnace, to which gas issuing from said producer through said outlet ispassed, an air inlet to said furnace and means including a' separateregulating mechanism for each air inlet for automatically proponproducerto the air supplied to the air inlet of said furnace, and means forsubjecting en pl I II an air inlet and a gas outlet and a fuel bed eachmechanism to an adjustable control force and for simultaneously andproportionally varying said forces, each of said mechanisms includingmeans for establishing a measure of the rate of air supply tothecorresponding inlet and means jointly responsive to said meas um and thecorresponding control force for regulating the last mentionedrate of aircombination a gas producer having interposed between said inlet andoutlet, a separate combustion furnace to which gas 'issuing from saidproducer through said -out let is passed, an airinlet to said furnace,means responsive to the rate of air flow through theair inlet to saidfurnace, means responsive to the rate of air flow through the air inletto said producer, and means jointly controlled by said flow responsivemeans for roportioning the air supplied to the air iniiet ofthe producerto the air supplied to the air inlet of said furnace.

' 4. Means for maintaining a desired ratio between two fluid rates offlow in two conduits, comprising in combination a means responsive tothe fluid rate of flow in each of said conduits, a potentiometerresistance associated with each conduit, means for causing a currentflow through each of said resis'tances, a switch member contacting witheach resistance and automatically adjusted ,by the corresponding flowresponsive means,

an electrical connection between said switch members, and means actuatedby current flow through such connection for adjusting the flow throughone of said conduits.

5. Means for maintaining a desired ratio between two fluid rates of flowthrough two conduits, comprising in combination a'means responsive tothe fluid rate of flow in each of said conduits, apotentiometerresistanceassociated with each conduit, a common source of currentsupplying current to each of said resistances, a switch membercontacting with each resistance and automatically adjusted by thecorresponding flow responsive means, an electrical connection betweensaid switch members and means actuated by current flow through suchconnection for adjusting the flow through one of said conduits.

6. In combination, a gas producer, air supplying means therefor, meanssupplying a diluent fluid to said producer, and means responsive to theamounts of air and diluent supplied for automatically proportioning theair and diluent so supplied.

7. In combination a gas producer, a plurality of gaseous supply meanstherefor and means responsive to the amounts of gaseous fluids suppliedby each for'automatically proportioning the gaseous flows, one to theother,

in fixed ratios, irrespective of the absolute magnitudes of the rates offlow.

8. In combination a gas producer and outlet connection therefrom, aplurality of inlet connections thereto andmeans responsive to the ratesof flow through the respectiveconnections whereby the rates of flowthrough said inlet and outlet connections are automatically proportionedin fixed ratios.

9. In combination a gas producer, a plurality of gaseous supply meanstherefor, a gas utilizing device, means responsive to the rates ofsupply and means responsive to the operation of the gas utilizingdevice, and means controlled by the two last mentioned means forregulating the gaseous supplies to the producer in fixed pro o,rtionstolone another, and

1n amount accor ing to the requirements of the utilizing device.

in the furnace, and means controlled by the 1 two last mentioned meansfor automatically controlling the respective rates of flow concurrentlyaccording to the temperature in the furnace. V

11. lhe combination with a pair of conduits, of a separate deflectingelement as-.

s'ociated with each conduit and deflected by, a

fluid flow throu h the conduit in proportion to a function 0 the rate ofsaid flow, and

8 1s,sue

means jointly controlled by the two deflecting elements .for adjustingthe flow in one "conduit so as to preserve a predetermined relationbetween the deflection of the two de 5 fleeting elements.

12. The combination with a pairof conduits, of a separate deflectingelement associated with each conduit and deflected b a fluid flowthrough the conduit in proportlon m to a function of the rate of saidflow,.and electromagnetic means jointly controlled by the two deflectingelements for adjusting the flow in one of the conduits as required tomaintain a predetermined relation between the fluid 15 rates of flow inthe two conduits.

13. The combination with a pair of conduits, of a separate differentialpressure gage including a deflecting element for each conduit soassociated therewith that the deflec- 20 tion of said element will beproportional to a function of the rate of fluid flow through theconduit, and means jointly controlled by the two deflecting elements foradjusting the flow in one conduit as required to'maintain n; apredetermined relation between the rates of flow in the two conduits.

Signed at Philadelphia, in the County of Philadelphia and State ofPennsylvania, this seventh day of October, 1931.

30 GEORGE H. GIBSON.

